1 /* sf_cos.c -- float version of s_cos.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  */
4 
5 /*
6  * ====================================================
7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8  *
9  * Developed at SunPro, a Sun Microsystems, Inc. business.
10  * Permission to use, copy, modify, and distribute this
11  * software is freely granted, provided that this notice
12  * is preserved.
13  * ====================================================
14  */
15 
16 #include "fdlibm.h"
17 
18 #ifdef __STDC__
cosf(float x)19 	float cosf(float x)
20 #else
21 	float cosf(x)
22 	float x;
23 #endif
24 {
25 	float y[2],z=0.0;
26 	__int32_t n,ix;
27 
28 	GET_FLOAT_WORD(ix,x);
29 
30     /* |x| ~< pi/4 */
31 	ix &= 0x7fffffff;
32 	if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);
33 
34     /* cos(Inf or NaN) is NaN */
35 	else if (!FLT_UWORD_IS_FINITE(ix)) return x-x;
36 
37     /* argument reduction needed */
38 	else {
39 	    n = __ieee754_rem_pio2f(x,y);
40 	    switch(n&3) {
41 		case 0: return  __kernel_cosf(y[0],y[1]);
42 		case 1: return -__kernel_sinf(y[0],y[1],1);
43 		case 2: return -__kernel_cosf(y[0],y[1]);
44 		default:
45 		        return  __kernel_sinf(y[0],y[1],1);
46 	    }
47 	}
48 }
49 
50 #ifdef _DOUBLE_IS_32BITS
51 
52 #ifdef __STDC__
cos(double x)53 	double cos(double x)
54 #else
55 	double cos(x)
56 	double x;
57 #endif
58 {
59 	return (double) cosf((float) x);
60 }
61 
62 #endif /* defined(_DOUBLE_IS_32BITS) */
63